Diplomatic efforts to end the Gulf conflict suffered a significant setback on Sunday when US President Donald Trump publicly rejected Iran's formal response to the latest American peace proposal, calling it "totally unacceptable" and renewing threats to resume military strikes. The Iranian counter-proposal had been conveyed through Pakistani mediators — part of a quartet also comprising Egypt, Saudi Arabia, and Türkiye — and was delivered after a final review by Iranian leadership.
Tehran's response, reported by the semi-official Tasnim news agency, proposed that the current phase of talks focus primarily on ending hostilities across all fronts, including in Lebanon, while leaving more contested issues — sanctions relief, the lifting of a US naval blockade on the Strait of Hormuz, and the nuclear programme — to later stages. The original US memorandum, a 14-point document presented the previous week, had called for a moratorium of up to 20 years on Iranian uranium enrichment, the transfer overseas of Iran's stockpile of highly enriched uranium (HEU), and the dismantling of nuclear facilities. According to the Wall Street Journal, Iran's counter-proposal offered a shorter enrichment moratorium, the export of only part of the HEU stockpile with the remainder to be diluted, and a rejection of facility dismantlement. Trump responded tersely on his Truth Social platform: "I have just read the response from Iran's so-called 'representatives'. I don't like it — totally unacceptable."
At the centre of the dispute is Iran's stockpile of more than 440 kilograms of uranium enriched to 60% purity — just a technical step from weapons grade, which the International Atomic Energy Agency (IAEA) says is stored deep underground in central Iran. Israeli Prime Minister Benjamin Netanyahu, in remarks aired Sunday on CBS, declared the war "not over" while that material remains in Iran, saying Trump had told him "I want to go in there" to secure it. Trump himself took a more measured public tone, suggesting that Space Force satellite surveillance was, for now, sufficient to monitor the sites. Iran's military, meanwhile, declared it was at "full readiness" to protect the stockpile, with one spokesperson warning against possible infiltration or helicopter-borne operations. Russian President Vladimir Putin added that Moscow's offer to receive Iran's enriched uranium as part of a negotiated settlement remains on the table.
The fragile ceasefire brokered by Pakistan — which came into effect on 8 April — showed new signs of strain throughout Sunday. The United Arab Emirates said it shot down two drones it attributed to Iran; Kuwait reported drones entering its airspace; and a separate drone attack ignited a small fire on a ship off the Qatari coast. Qatar's foreign ministry condemned the ship strike as a "dangerous and unacceptable escalation", while the country's prime minister urged Iran's foreign minister not to use the Strait of Hormuz — the narrow waterway through which a significant share of the world's oil and liquefied natural gas passes — as a tool of pressure. Iran has largely kept the strait closed since the outbreak of war on 28 February, when US and Israeli forces launched initial strikes.
The diplomatic picture is complicated by competing mediating tracks. Qatar has stepped up as a complementary channel alongside the Pakistan-led quartet, and in a symbolic gesture, Tehran permitted a Qatari liquefied natural gas tanker destined for Pakistan to pass through the strait. Britain and France are set to co-chair a meeting of over 40 defence ministers on Tuesday to discuss plans for an international maritime security mission in the strait, a move Iran has already warned against. Trump faces considerable pressure to stabilise the situation before a scheduled visit to China later this week; Beijing, a major buyer of Iranian oil, has been pushing for an end to hostilities and the reopening of the waterway. Whether the diplomatic process can survive the latest rupture remains deeply uncertain.